Typically, the cabinet of a portable television (TV) receiver is made up of a pair of injection molded halves--the cabinet front and the back cover, which are molded from a suitable thermoplastic material (e.g., polystyrene). The picture tube and the chassis carrying the electronics are mounted to the cabinet front. The back cover is then secured to the front cover to complete the instrument assembly.
The fastening means used for attaching the back cover to the cabinet front must fulfill a number of basic requirements. The fastening means must withstand shock and vibration encountered during handling and shipping. The fastening means must allow quick disengagement of the back cover from the cabinet front to permit servicing of the television instrument, and it must allow subsequent re-assembly of the back cover. Moreover, the fastening means must not permit inadvertent insertion of a tool into the cabinet enclosure to reduce safety hazards.
Traditionally, the TV cabinet halves have been joined together with screw type fasteners, since they meet the above-mentioned basic requirements. However, a disadvantage of the screw type fasteners is that they are not amenable to automatic assembly of the television instrument. The assembly time required to install the screws is relatively large. Furthermore, relatively sophisticated equipment is required for automatically tightening the screws.